Troubles with shorepower
 

We are having difficulties figuring out the shorepower. Everything
was working fine on 30A, but now that we have moved to a new dock
where there is only 110 we have attached our pig tail to take the 30
to 110 but it trips the breaker on the dock as soon as we plug it in.
We tried using the neighbour's pigtail (which works for him) and it
still trips it. We have the Xantrex inverter/charger and have
adjusted the powershare level to 10 (from 30).

Any ideas?

Troubles with shorepower
 

On Sat, 8 Dec 2007 15:08:46 -0800 (PST), Itinerant
wrote:

We are having difficulties figuring out the shorepower. Everything
was working fine on 30A, but now that we have moved to a new dock
where there is only 110 we have attached our pig tail to take the 30
to 110 but it trips the breaker on the dock as soon as we plug it in.
We tried using the neighbour's pigtail (which works for him) and it
still trips it. We have the Xantrex inverter/charger and have
adjusted the powershare level to 10 (from 30).

Any ideas?

More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

If so, first thing I would do would be to turn off all the AC panel
circuit breakers - both main and branch. Then connect the shore power
cord. If the shore breaker trips, you have a wiring problem in the 30
- 15 amp adaptor, the dock outlet (unlikely) or on the boat (also
unlikely, if things worked when plugged into a 30 amp outlet.)

If the shore breaker hasn't tripped, turn on the branch circuit
breakers one at a time, til it does - then you _may_ have found the
source of the problem.

One local marina uses the 15 amp household-style outlets, and has
several outlets on one breaker - this caused blown breakers several
times on a club cruise there, as we all wanted to run heaters - I
think we eventually got the boats distributed between breakers, and
heaters turned down, so we could all get some heat.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Troubles with shorepower
 

HELLO PETER, THANKS FOR REPLYING. SORRY IF WE SOUND CONFUSING WE HAVE
ONLY HAD THE BOAT FOR A WEEK AND ARE NEW TO HAVING A POWER BOAT, OUR
PREVIOUS SAIL BOAT WAS VERY SIMPLE WITH FEW GADGETS =) THE PREVIOUS
OWNER DID NOT HAVE THE BOAT FOR VERY LONG, SO HE DOES NOT REALLY HAVE
MANY ANSWERS FOR US EITHER.

More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

YES THAT IS CORRECT THE DOCK ONLY AS A HOUSEHOLD STYLE 15 AMP OUTLET
(WE ARE AT HEATHER MARINE IN FALSE CREEK)

If so, first thing I would do would be to turn off all the AC panel
circuit breakers - both main and branch. Then connect the shore power
cord. If the shore breaker trips, you have a wiring problem in the 30
- 15 amp adaptor, the dock outlet (unlikely) or on the boat (also
unlikely, if things worked when plugged into a 30 amp outlet.)

WE DID TURN EVERYTHING OFF AND PLUGGED IN AND TRIPPED THE BREAKER ON
THE DOCK. WE TRIED OUR NEIGHBOUR BOAT'S ADOPTOR ON OUR CABLE (WHICH I
MIGHT ADD IS NEW) AND IT STILL TRIPPED THE DOCK BREAKER. (ON THE DOCK
AT GRANVILLE ISLAND WE HAD NO PROBLEMS WITH USING THE 30 AMP.)

WE HAD SET THE (XANTREX LINK 1000) POWER SHARE VALUE TO A NUMBER OF
VALUES -- DEFAULT IS 30 -- WE THINK WE WILL TRY SETTING IT TO 15 AND
TRY AGAIN? I'M THINKING THAT WE DON'T HAVE SOMETHING SET CORRECT ON
THIS LINK 1000.

BTW -- WE ARE INTERESTED IN THE VANCOUVER POWER SQUADRON WHICH I SEE
YOU HAVE A LINK TO ON THE BOTTOM OF YOUR POST, ARE YOU A MEMBER? IS
THERE AN EVENING THAT WE CAN COME AND CHECK IT OUT?

THANKS AGAIN.


If the shore breaker hasn't tripped, turn on the branch circuit
breakers one at a time, til it does - then you _may_ have found the
source of the problem.

One local marina uses the 15 amp household-style outlets, and has
several outlets on one breaker - this caused blown breakers several
times on a club cruise there, as we all wanted to run heaters - I
think we eventually got the boats distributed between breakers, and
heaters turned down, so we could all get some heat.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info :http://vancouver-webpages.com/nnq
GPS and NMEA info:http://vancouver-webpages.com/peter
Vancouver Power Squadron:http://vancouver.powersquadron.ca

Troubles with shorepower
 

Itinerant wrote:
HELLO PETER, THANKS FOR REPLYING. SORRY IF WE SOUND CONFUSING WE HAVE
ONLY HAD THE BOAT FOR A WEEK AND ARE NEW TO HAVING A POWER BOAT, OUR
PREVIOUS SAIL BOAT WAS VERY SIMPLE WITH FEW GADGETS =) THE PREVIOUS
OWNER DID NOT HAVE THE BOAT FOR VERY LONG, SO HE DOES NOT REALLY HAVE
MANY ANSWERS FOR US EITHER.

Ouch! That's loud!

Amps, volts watts, ohms, aren't they all the same?


Dennis.

Troubles with shorepower
 

"Itinerant" wrote in message
...
WE DID
turned volume right down on the rest:-))

If the shore breaker hasn't tripped, turn on the branch circuit
breakers one at a time, til it does - then you _may_ have found the
source of the problem.

One local marina uses the 15 amp household-style outlets, and has
several outlets on one breaker - this caused blown breakers several
times on a club cruise there, as we all wanted to run heaters - I
think we eventually got the boats distributed between breakers, and
heaters turned down, so we could all get some heat.

My boat came from USA and has 110 volt equipment which I wanted to retain so
I installed a 230/110 volt transformer (2kw capacity) to bring down the
local 230 volts to 110.
Every time I plugged it in it tripped the marina breakers. I spoke to the
transformer people who said that this is a common problem now that breakers
have largely replaced the old fashioned fuses in these marinas. Some of
these breakers are very hair trigger in their response to over current.
They said that even my small transformer takes no less than 200 amps while
it builds up its flux. This only lasts for 5 milliseconds but is enough to
trip the more sensitive type of breakers whereas it would not trip an old
fashioned fuse as these react more slowly and would not have time to heat up
before the transformer current went back to zero.
The solution was to introduce a 'current limiter' in series with the primary
of the transformer. This is a very small component that looks like, and
probably is, a condenser-a blob about 1/2" diameter ith two wires sticking
out. Once powered up the only current the transformer takes is that due to
the load-max 2kw.
End of problem for me, but to be sure I put two of them in series bcause it
is highly embarassing to shut down the power of the whole dock finger when
other people are also plugged in..
So, I suggest that your inverter or whatever you are powering up has the
same current surge on starting and may well be cured the same way. Talk to
the makers and see.

Troubles with shorepower
 

In article , Itinerant wrote:
HELLO PETER, THANKS FOR REPLYING. SORRY IF WE SOUND CONFUSING WE HAVE

[snip]

Please don't shout. It makes for very unpleasant reading.

Justin.

--
Justin C, by the sea.

Troubles with shorepower
 

"Roger Long" wrote in news:475bd5bc$0$27918
:

Typing in all caps is considered shouting and quite rude.



WHAT?!

Larry
--
Any more news on Grandpa??

Troubles with shorepower
 

On Sat, 08 Dec 2007 17:19:29 -0800, Peter Bennett
wrote:

More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

There is also the twenty amp outlet. The plug's blades are at ninety
degrees. Only such plugs I have ever seen were for window type air
conditioners. They make the outlets with the 'T' shaped holes to take
both those and the fifteen amp ones with the parallel blades.

Casady

Troubles with shorepower
 

On Sat, 8 Dec 2007 21:25:32 -0800 (PST), Itinerant
wrote:

HELLO PETER, THANKS FOR REPLYING. SORRY IF WE SOUND CONFUSING WE HAVE
ONLY HAD THE BOAT FOR A WEEK AND ARE NEW TO HAVING A POWER BOAT, OUR
PREVIOUS SAIL BOAT WAS VERY SIMPLE WITH FEW GADGETS =) THE PREVIOUS
OWNER DID NOT HAVE THE BOAT FOR VERY LONG, SO HE DOES NOT REALLY HAVE
MANY ANSWERS FOR US EITHER.

Your caps lock key seems to be broken...

More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

YES THAT IS CORRECT THE DOCK ONLY AS A HOUSEHOLD STYLE 15 AMP OUTLET
(WE ARE AT HEATHER MARINE IN FALSE CREEK)

If so, first thing I would do would be to turn off all the AC panel
circuit breakers - both main and branch. Then connect the shore power
cord. If the shore breaker trips, you have a wiring problem in the 30
- 15 amp adaptor, the dock outlet (unlikely) or on the boat (also
unlikely, if things worked when plugged into a 30 amp outlet.)

WE DID TURN EVERYTHING OFF AND PLUGGED IN AND TRIPPED THE BREAKER ON
THE DOCK. WE TRIED OUR NEIGHBOUR BOAT'S ADOPTOR ON OUR CABLE (WHICH I
MIGHT ADD IS NEW) AND IT STILL TRIPPED THE DOCK BREAKER. (ON THE DOCK
AT GRANVILLE ISLAND WE HAD NO PROBLEMS WITH USING THE 30 AMP.)

The marina's breaker trips even with your main breaker turned off? If
so, something is seriously wrong.


WE HAD SET THE (XANTREX LINK 1000) POWER SHARE VALUE TO A NUMBER OF
VALUES -- DEFAULT IS 30 -- WE THINK WE WILL TRY SETTING IT TO 15 AND
TRY AGAIN? I'M THINKING THAT WE DON'T HAVE SOMETHING SET CORRECT ON
THIS LINK 1000.

The Link 1000 is a battery monitor/control panel used with a Xantrex
Fredom-series inverter/charger.

If the marina outlet has a 15 amp breaker, you should set the power
share setting to less than 15 amps. If you can reduce the maximum
charger current to 50 amps or less, you should do that as well. I
have a Prosine 2.0 inverter/charger on my boat, which has an "Source
Breaker Rating" (or somesuch) setting. If you have something like
that, set it below 15 amps.

However, none of this will help if the marina breaker trips even with
the boat's main breaker off.

BTW -- WE ARE INTERESTED IN THE VANCOUVER POWER SQUADRON WHICH I SEE
YOU HAVE A LINK TO ON THE BOTTOM OF YOUR POST, ARE YOU A MEMBER? IS
THERE AN EVENING THAT WE CAN COME AND CHECK IT OUT?

THANKS AGAIN.

Yes, I'm as member of VPS (webmaster and radio instructor). We have a
christmas potluck dinner Monday Dec 10 at FCYC. Give me a phone call
for further information, or if you'd like me to come have a look at
your electrical problem - phone number is on the VPS website, under
"officers".


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Troubles with shorepower
 

On Sat, 8 Dec 2007 21:25:32 -0800 (PST), Itinerant
wrote:

HELLO PETER, THANKS FOR REPLYING. SORRY IF WE SOUND CONFUSING WE HAVE
ONLY HAD THE BOAT FOR A WEEK AND ARE NEW TO HAVING A POWER BOAT, OUR
PREVIOUS SAIL BOAT WAS VERY SIMPLE WITH FEW GADGETS =) THE PREVIOUS
OWNER DID NOT HAVE THE BOAT FOR VERY LONG, SO HE DOES NOT REALLY HAVE
MANY ANSWERS FOR US EITHER.

Another thought: if you have a hot water tank, leave it off - no point
wasting power keeping the water hot when you won;t be using it, and it
does consume a lot of power, and it won't be sensed by the Link 1000's
current sharing scheme.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Troubles with shorepower
 

On Sat, 8 Dec 2007 21:25:32 -0800 (PST), Itinerant
wrote:

......
cord. If the shore breaker trips, you have a wiring problem in the 30
- 15 amp adaptor, the dock outlet (unlikely) or on the boat (also
unlikely, if things worked when plugged into a 30 amp outlet.)

WE DID TURN EVERYTHING OFF AND PLUGGED IN AND TRIPPED THE BREAKER ON
THE DOCK.

......


Here's a lifeline: if you blow a shore supply breaker when your stuff
is all OFF, you have the famous "American Neutral to Ground"
connection.

That's the way American consumers are wired, after all!
Get an electrician to fix it up for preference

Regards



Brian Whatcott Altus OK

Troubles with shorepower
 

"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing current.

Volt meter? Inline? To measure current? Huh?

Troubles with shorepower
 

On 2007-12-10 08:30:09 -0500, Paul Cassel
said:

Ernest Scribbler wrote:
"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing
current.

Volt meter? Inline? To measure current? Huh?

Yeah, stupid me. I mean multimeter.

Hmmm. You have a multi-meter that'll directly measure more than a few
milliwatts?

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

Troubles with shorepower
 

On 2007-12-09 14:46:19 -0500, Brian Whatcott said:

On Sat, 8 Dec 2007 21:25:32 -0800 (PST), Itinerant
wrote:

.....
If the shore breaker trips, you have a wiring problem in the 30 - 15
amp adaptor, the dock outlet (unlikely) or on the boat (also unlikely,
if things worked when plugged into a 30 amp outlet.)

WE DID TURN EVERYTHING OFF AND PLUGGED IN AND TRIPPED THE BREAKER ON THE DOCK.

Here's a lifeline: if you blow a shore supply breaker when your stuff
is all OFF, you have the famous "American Neutral to Ground" connection.

I've found it impossible to respond to the posts with much of that
shouting, but a test I'd like to see is what happens if the cord isn't
plugged into the boat, but both pigtails on shore (if I'm reading
things correctly) are. If that trips the breaker, the problem is one of
the outlets OR the pigtail itself, nothing on the boat.

If the breaker trips only when plugged into the boat AND the boat's
breaker doesn't trip, I'd carefully examine from the plug to the
distribution panel for a shorted wire. The receptacle is the most
likely culprit, but there could be chafing down below.

I'd also test to see if another boat successfully plugged in elsewhere
could draw from his.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

Troubles with shorepower
 

On Mon, 10 Dec 2007 01:57:32 GMT, Jere Lull wrote:

On 2007-12-10 08:30:09 -0500, Paul Cassel
said:

Ernest Scribbler wrote:
"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing
current.

Volt meter? Inline? To measure current? Huh?

Yeah, stupid me. I mean multimeter.

Hmmm. You have a multi-meter that'll directly measure more than a few
milliwatts?

Mine is a digital with a ten amp fuse on the Amp function. Fluke 87 as
a matter of fact. All the professional heating and cooling guys, and
the appliance repairman, seem to have one like it.

Casady

Troubles with shorepower
 

On Mon, 10 Dec 2007 01:57:32 GMT, Jere Lull wrote:

On 2007-12-10 08:30:09 -0500, Paul Cassel
said:

Ernest Scribbler wrote:
"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing
current.

Volt meter? Inline? To measure current? Huh?

Yeah, stupid me. I mean multimeter.

Hmmm. You have a multi-meter that'll directly measure more than a few
milliwatts?

Multimeter? In-line? To measure power? Huh?
:-)
Ho-hum....A 10 Amp range is not unusual in a digital MM
But a power scale is rather unusual - except the dB scale that makes
some load presumptions - that you may be referring to?

Brian W

Troubles with shorepower
 

Thank you for all of your posts, and sorry again for SHOUTING!

We tried many different senarios with no luck, we believe that we have
ruled out the cords and the pigtail. We have not tried to plug in
without being plugged into the boat ... interesting we may have to
take a walk tonight to try that out. We qustion that it would be the
receptacle as the 30 Amp worked fine on the other dock. Today when we
were at the boat we turned the battery seletor to off, and made sure
all circuits were off and both main switches and it still tripped the
box on the dock (instentaniously, before the plug was even half way
pushed in). We are starting to think that all it could be is a ground
problem -- possibly "American Neutral to Ground" as mentioned above.

We are currently running an outdoor extention cord from the dock to
our cabin heater. The system was just installed this past April and
we have found the mechanics receipt (yippy!), so tomorrow we will try
and get in touch with him to see if he can help us out.

Craig & Tanya Petterson
Vancouver BC Canada

Troubles with shorepower
 

"Richard Casady" wrote
Mine is a digital with a ten amp fuse on the Amp function. Fluke 87 as
a matter of fact. All the professional heating and cooling guys, and
the appliance repairman, seem to have one like it.

That's well and good, but an ammeter with a 10A fuse may not be very helpful
in a circuit that's tripping a 15A breaker. I think I'd start by removing
all the power and using the 87's ohm meter function.

Troubles with shorepower
 

"Brian Whatcott" wrote
the famous "American Neutral to Ground" connection.
That's the way American consumers are wired, after all!

Say what?

Troubles with shorepower
 

On Sun, 9 Dec 2007 22:29:15 -0500, "Ernest Scribbler"
wrote:

"Brian Whatcott" wrote
the famous "American Neutral to Ground" connection.
That's the way American consumers are wired, after all!

Say what?


What is it that you don't understand? See code of practice for first
drop at domestic distribution transformer.....

Brian W

Troubles with shorepower
 

Itinerant wrote:
We are having difficulties figuring out the shorepower. Everything
was working fine on 30A, but now that we have moved to a new dock
where there is only 110 we have attached our pig tail to take the 30
to 110 but it trips the breaker on the dock as soon as we plug it in.
We tried using the neighbour's pigtail (which works for him) and it
still trips it. We have the Xantrex inverter/charger and have
adjusted the powershare level to 10 (from 30).

Any ideas?

after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing
current. I'll be you are. You will need to trace / fix that.

You probably have an unswitched appliance

Troubles with shorepower
 

Ernest Scribbler wrote:
"Paul Cassel" wrote
after shutting off all breakers in the 120 v circuit, put a voltmeter
inline with the pigtail to see if, in fact, you are still drawing current.

Volt meter? Inline? To measure current? Huh?


Yeah, stupid me. I mean multimeter.

Troubles with shorepower
 

On Dec 9, 7:40 pm, Brian Whatcott wrote:
On Sun, 9 Dec 2007 22:29:15 -0500, "Ernest Scribbler"

wrote:
"Brian Whatcott" wrote
the famous "American Neutral to Ground" connection.
That's the way American consumers are wired, after all!

Say what?

What is it that you don't understand? See code of practice for first
drop at domestic distribution transformer.....

Brian W


I think this is the problem.

Theoretically, both "sides" of the AC should be "floating" - that is,
both Line (black) and Neutral (white) should only be connected to the
load, not to ground, or case, or anything. The third wire is Ground
(green) and should be connected to ground/chassis/frame/etc.

In the "two-wire" system (with the polarized plug), the Neutral is
also ground. So... a lot of systems connect neutral to ground.
Everything goes OK until some Bright Individual says both AC lines are
floating so it doesn't matter which one is which.... so you end up
with Line going to Neutral and vice versa. This works OK until someone
grounds the Neutral, and POOF.

I suspect either your boat, your marina, or your cords have line and
neutral reversed, and then grounded. You or a licensed Electrician
needs to check what wire goes to which connection on all the plugs and
connectors.

BTW: If you're a Vancouver boater, check out the BC Boatnet forum! :)

druid - "Coatue" Crown 28
http://www.bcboatnet.org

Troubles with shorepower
 

"Brian Whatcott" wrote
What is it that you don't understand?
See code of practice for first
drop at domestic distribution transformer.....

I understand that ground and neutral are connected to a common bus at the
service entrance. Are you saying the OP's problem may be that ground and
neutral are connected at his shore power connection? That would just be
plain wrong. I'm not trying to be confrontational, just trying to understand
what you're getting at.

Troubles with shorepower
 

On Mon, 10 Dec 2007 16:03:27 -0500, "Ernest Scribbler"
wrote:

"Brian Whatcott" wrote
What is it that you don't understand?
See code of practice for first
drop at domestic distribution transformer.....

I understand that ground and neutral are connected to a common bus at the
service entrance. Are you saying the OP's problem may be that ground and
neutral are connected at his shore power connection? That would just be
plain wrong. I'm not trying to be confrontational, just trying to understand
what you're getting at.


Sadly, though just the first drop is specified to cross connect, in
older practice, follow on drops were also sometimes connected.
As you say, it's just plain wrong.

Brian W

Troubles with shorepower
 

On Dec 9, 8:16 pm, (Richard Casady) wrote:
On Sat, 08 Dec 2007 17:19:29 -0800, Peter Bennett

wrote:
More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

There is also the twenty amp outlet. The plug's blades are at ninety
degrees. Only such plugs I have ever seen were for window type air
conditioners. They make the outlets with the 'T' shaped holes to take
both those and the fifteen amp ones with the parallel blades.

Casady

Here in Canada we often use those 'horizontal pin' plugs for 230
volts.
In our garage, for example, we have 115 volt vertical pin outlets and
a 230 volt so we can plug in both types of tools. Both are breakered
at 15 amps.
On a workshop workbench we also have both.

Troubles with shorepower
 

"Edgar" wrote in message
...

"Itinerant" wrote in message
...


FWIW,

I have discovered that some inverters that are based on switching power
supply technology just don't get along well with ground fault (GFI)
protected circuits. When power is first applied, and within the first half
cycle of the 60Hz, the impedance of the switching power supply appears as a
dead short to ground, tripping the GFI type breaker. There's nothing wrong
with the circuit, it's just a characteristic of the supply type.

Xantrex happens to be one that I've experienced problems with before in
this regard.

Eisboch

Troubles with shorepower
 

"Eisboch" wrote
I have discovered that some inverters that are based on switching power
supply technology just don't get along well with ground fault (GFI)
protected circuits.

Do marinas commonly use GFCIs on their shore power circuits?

Troubles with shorepower
 

"Eisboch" wrote in
:

the impedance of the switching power supply appears as a
dead short to ground, tripping the GFI type breaker. There's
nothing
wrong with the circuit, it's just a characteristic of the
supply type.




The input of any switching power supply is merely a full wave
bridge rectifier and some LARGE electrolytic capacitors, which
are what causes the huge surge when you plug them in...charging
those caps.

They use large caps for a reason.....to reduce the effects of
powerline pulses, especially OFF pulses that blink your lights.
The large caps can hold up the output DC for several hundred
milliseconds during those brief power "blinks".

Unfortunately, the idiots are trying to see how few parts they
can make them out of so leave out any surge-reducing varistors or
even low value surge resistors from the primary circuit that
would stop the huge pulse and plug-in-arcing.

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE

Troubles with shorepower
 

"Ernest Scribbler" wrote in
:

Do marinas commonly use GFCIs on their shore power circuits?




Not around here. All the breakers at our marinas are the old rusty
types with the half-broken-off handles...(c;

GFCI's are way too expensive for marinas, trying to extract maximum
profits in the shortest length of time.

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE

Troubles with shorepower
 

Larry wrote:
"Eisboch" wrote in
:


the impedance of the switching power supply appears as a
dead short to ground, tripping the GFI type breaker. There's

nothing

wrong with the circuit, it's just a characteristic of the

supply type.




The input of any switching power supply is merely a full wave
bridge rectifier and some LARGE electrolytic capacitors, which
are what causes the huge surge when you plug them in...charging
those caps.

They use large caps for a reason.....to reduce the effects of
powerline pulses, especially OFF pulses that blink your lights.
The large caps can hold up the output DC for several hundred
milliseconds during those brief power "blinks".

Unfortunately, the idiots are trying to see how few parts they
can make them out of so leave out any surge-reducing varistors or
even low value surge resistors from the primary circuit that
would stop the huge pulse and plug-in-arcing.

Larry


Wouldn't adding something like a starting capacitor fix that?

Troubles with shorepower
 

cavelamb himself wrote in
:

Wouldn't adding something like a starting capacitor fix that?



No, the circuit is just too simple...4 diodes in a bridge, caps
across the DC output of the rectifiers about 160VDC to power the
power MOSFET switching transistors running at 100 Khz or so. The
custom IC made to run all this measures the output DC volts and
varies the pulse width fed to the power transistors to regulate
the voltage. There's nothing analog about it. The MOSFETS are
either OFF, no heat generated or SATURATED, very little heat
generated because they are nearly a short at saturation...full
on. The DC output comes from another set of higher frequency
rectifiers hooked to a high frequency toroid transformer,
sometimes with more than one secondary winding like the DC power
supply in your desktop computer to get different voltages and
polarities....

When the load increases and output voltage TRIES to drop, the IC
senses this very fast and widens the pulse with to the switching
transistors, pulling the voltage back up with more power to the
toroid transformer. If the line voltage changes, the output also
tries to change, causing the sensing of the IC to vary the pulse
width in the appropriate direction to compensate. Some switching
power supplies, like those very light wall bricks that run and
charge your cellphones, pocket PCs, and laptop computers will
tolerate a voltage change so huge you don't even have to worry
about what line voltage you're plugging it into from 80VAC to
280VAC! If you plug it into 115 in USA, the pulse width is wider
than if you plug it into 240 in Europe. It doesn't care what
frequency because we're just going to directly rectify AC into DC
and feed it to the big input caps to store for the switchers.

What's hilarious in all this is someone with a very wide input
Switching powersupply plugging it into some kind of "SURGE
PROTECTOR" to keep any power line surges from "damaging" it. The
switcher could care less! If a big pulse of voltage comes into
it, the huge input caps just absorb it, turning the pulse into
more power for the switchers to use. Hell, if you surge it at
300V that's well within "normal" peak voltage on the 240VAC
system it was also designed for! The surge protector IS the
power supply itself! It's output is steady as a rock until the
big input filter caps drop below about 70VDC...on power down.

Switchers are neat.

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE

Troubles with shorepower
 

On Sun, 9 Dec 2007 22:26:58 -0500, "Ernest Scribbler"
wrote:

"Richard Casady" wrote
Mine is a digital with a ten amp fuse on the Amp function. Fluke 87 as
a matter of fact. All the professional heating and cooling guys, and
the appliance repairman, seem to have one like it.

That's well and good, but an ammeter with a 10A fuse may not be very helpful
in a circuit that's tripping a 15A breaker. I think I'd start by removing
all the power and using the 87's ohm meter function.

A good digital you can plug it into a wall socket with it on Ohms
without damage.

Casady

Troubles with shorepower
 

On Tue, 11 Dec 2007 14:59:12 -0800 (PST), terry
wrote:

On Dec 9, 8:16 pm, (Richard Casady) wrote:
On Sat, 08 Dec 2007 17:19:29 -0800, Peter Bennett

wrote:
More details would be useful. As it stands, your description doesn't
make sense to me, as the common North American 30 amp shore power
service _is_ 110 volts. Do you mean that the boat has a 30 amp power
inlet and shore power cord, but the dock only has a household-style 15
amp/110V outlet?

There is also the twenty amp outlet. The plug's blades are at ninety
degrees. Only such plugs I have ever seen were for window type air
conditioners. They make the outlets with the 'T' shaped holes to take
both those and the fifteen amp ones with the parallel blades.

Casady

Here in Canada we often use those 'horizontal pin' plugs for 230
volts.
In our garage, for example, we have 115 volt vertical pin outlets and
a 230 volt so we can plug in both types of tools. Both are breakered
at 15 amps.
On a workshop workbench we also have both.

Come to think of it, the 20 Amp ones have one blade each way, and the
two blade horizontal are 220 in the US as well. I think. Been a while
since I last wired any outlets, but think that I now have it right.

Casady

Troubles with shorepower
 

"Richard Casady" wrote
an ammeter with a 10A fuse may not be very helpful
in a circuit that's tripping a 15A breaker

A good digital you can plug it into a wall socket with it on Ohms
without damage.

I'll keep that in mind in case I ever want to try it.

My point is that, at best, a current measurement in this case is only going
to tell you what you already know.

Troubles with shorepower
 

On Wed, 19 Dec 2007 11:47:59 -0500, "Ernest Scribbler"
wrote:

"Richard Casady" wrote
an ammeter with a 10A fuse may not be very helpful
in a circuit that's tripping a 15A breaker

A good digital you can plug it into a wall socket with it on Ohms
without damage.

I'll keep that in mind in case I ever want to try it.

It isn't something you try. It's always carelessness. It's nice that
it survives a dumb move

My point is that, at best, a current measurement in this case is only going
to tell you what you already know.

That is true. At one time you could buy a shunt to extend the range on
a meter. I bet they still sell them.

Casady

Troubles with shorepower
 

On Wed, 19 Dec 2007 17:02:24 GMT, (Richard
Casady) wrote:

That is true. At one time you could buy a shunt to extend the range on
a meter. I bet they still sell them.

Current shunts are widely available from a number of sources:

http://www.google.com/search?hl=en&q=ac+current+shunts

Or you can make your own:

http://www.uoguelph.ca/~antoon/gadge...ts/shunts.html